/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup   PIOS_OVERO OVERO Functions
 * @brief PIOS interface to read and write to overo
 * @{
 *
 * @file       pios_overo.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
 * @brief      Hardware Abstraction Layer for Overo communications
 * @see        The GNU Public License (GPL) Version 3
 * @notes
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <pios.h>

#ifdef PIOS_INCLUDE_OVERO

/**
 * Configures the SPI device to use a double buffered DMA for transferring
 * data.  At the end of each transfer (NSS goes high) it makes sure to reset
 * the DMA counter to the beginning of each packet and swap to the next
 * buffer
 */

#ifdef PIOS_INCLUDE_SPI

#include <pios_overo_priv.h>

#define PACKET_SIZE 1024

/* Provide a COM driver */
static void PIOS_OVERO_RegisterRxCallback(uint32_t overo_id, pios_com_callback rx_in_cb, uint32_t context);
static void PIOS_OVERO_RegisterTxCallback(uint32_t overo_id, pios_com_callback tx_out_cb, uint32_t context);
static void PIOS_OVERO_TxStart(uint32_t overo_id, uint16_t tx_bytes_avail);
static void PIOS_OVERO_RxStart(uint32_t overo_id, uint16_t rx_bytes_avail);

const struct pios_com_driver pios_overo_com_driver = {
    .set_baud   = NULL,
    .tx_start   = PIOS_OVERO_TxStart,
    .rx_start   = PIOS_OVERO_RxStart,
    .bind_tx_cb = PIOS_OVERO_RegisterTxCallback,
    .bind_rx_cb = PIOS_OVERO_RegisterRxCallback,
};

// ! Data types
enum pios_overo_dev_magic {
    PIOS_OVERO_DEV_MAGIC = 0x85A3834A,
};

struct pios_overo_dev {
    enum pios_overo_dev_magic   magic;
    const struct pios_overo_cfg *cfg;

    int8_t   writing_buffer;
    uint32_t writing_offset;

    uint32_t packets;

    uint8_t  tx_buffer[2][PACKET_SIZE];
    uint8_t  rx_buffer[2][PACKET_SIZE];

    pios_com_callback rx_in_cb;
    uint32_t rx_in_context;
    pios_com_callback tx_out_cb;
    uint32_t tx_out_context;
};

#if defined(PIOS_INCLUDE_FREERTOS)
// ! Private methods
static void PIOS_OVERO_WriteData(struct pios_overo_dev *overo_dev);
static bool PIOS_OVERO_validate(struct pios_overo_dev *overo_dev);
static struct pios_overo_dev *PIOS_OVERO_alloc(void);

static bool PIOS_OVERO_validate(struct pios_overo_dev *overo_dev)
{
    return overo_dev->magic == PIOS_OVERO_DEV_MAGIC;
}

static struct pios_overo_dev *PIOS_OVERO_alloc(void)
{
    struct pios_overo_dev *overo_dev;

    overo_dev = (struct pios_overo_dev *)pios_malloc(sizeof(*overo_dev));
    if (!overo_dev) {
        return NULL;
    }

    overo_dev->rx_in_cb       = 0;
    overo_dev->rx_in_context  = 0;
    overo_dev->tx_out_cb      = 0;
    overo_dev->tx_out_context = 0;
    overo_dev->packets = 0;
    overo_dev->magic   = PIOS_OVERO_DEV_MAGIC;
    return overo_dev;
}

/**
 * Take data from the PIOS_COM buffer and transfer it to the currently inactive DMA
 * circular buffer
 */
static void PIOS_OVERO_WriteData(struct pios_overo_dev *overo_dev)
{
    // TODO: How do we protect against the DMA buffer swapping midway through adding data
    // to this buffer.  If we were writing at the beginning it could cause a weird race.
    if (overo_dev->tx_out_cb) {
        int32_t max_bytes = PACKET_SIZE - overo_dev->writing_offset;

        if (max_bytes > 0) {
            uint16_t bytes_added;
            bool tx_need_yield = false;
            uint8_t *writing_pointer = &overo_dev->tx_buffer[overo_dev->writing_buffer][overo_dev->writing_offset];

            bytes_added = (overo_dev->tx_out_cb)(overo_dev->tx_out_context, writing_pointer, max_bytes, NULL, &tx_need_yield);

#if defined(OVERO_USES_BLOCKING_WRITE)
            if (tx_need_yield) {
                vPortYieldFromISR();
            }
#endif
            overo_dev->writing_offset += bytes_added;
        }
    }
}

/**
 * Called at the end of each DMA transaction.  Refresh the flag indicating which
 * DMA buffer to write new data from the PIOS_COM fifo into the buffer
 */
void PIOS_OVERO_DMA_irq_handler(uint32_t overo_id)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    if (!PIOS_OVERO_validate(overo_dev)) {
        return;
    }

    DMA_ClearFlag(overo_dev->cfg->dma.tx.channel, overo_dev->cfg->dma.irq.flags);

    overo_dev->writing_buffer = 1 - DMA_GetCurrentMemoryTarget(overo_dev->cfg->dma.tx.channel);
    overo_dev->writing_offset = 0;

/*	bool rx_need_yield;
        // Get data from the Rx buffer and add to the fifo
        (void) (overo_dev->rx_in_cb)(overo_dev->rx_in_context,
                                                                 &overo_dev->rx_buffer[overo_dev->writing_buffer][0],
                                                                PACKET_SIZE, NULL, &rx_need_yield);

        if(rx_need_yield) {
                vPortYieldFromISR();
        }

        // Fill the buffer with known value to prevent rereading these bytes
        memset(&overo_dev->rx_buffer[overo_dev->writing_buffer][0], 0xFF, PACKET_SIZE);
 */
    // Fill the buffer with known value to prevent resending any bytes
    memset(&overo_dev->tx_buffer[overo_dev->writing_buffer][0], 0xFF, PACKET_SIZE);

    // Load any pending bytes from TX fifo
    PIOS_OVERO_WriteData(overo_dev);

    overo_dev->packets++;
}

/**
 * Debugging information to check how it is runnign
 */
int32_t PIOS_OVERO_GetPacketCount(uint32_t overo_id)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    PIOS_Assert(PIOS_OVERO_validate(overo_dev));

    return overo_dev->packets;
}

/**
 * Debugging information to check how it is runnign
 */
int32_t PIOS_OVERO_GetWrittenBytes(uint32_t overo_id)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    PIOS_Assert(PIOS_OVERO_validate(overo_dev));

    return overo_dev->writing_offset;
}

/**
 * Initialise a single Overo device
 */
int32_t PIOS_OVERO_Init(uint32_t *overo_id, const struct pios_overo_cfg *cfg)
{
    PIOS_DEBUG_Assert(overo_id);
    PIOS_DEBUG_Assert(cfg);

    struct pios_overo_dev *overo_dev;

    overo_dev = (struct pios_overo_dev *)PIOS_OVERO_alloc();
    if (!overo_dev) {
        goto out_fail;
    }

    /* Bind the configuration to the device instance */
    overo_dev->cfg = cfg;
    overo_dev->writing_buffer = 1; // First writes to second buffer

    /* Put buffers to a known state */
    memset(&overo_dev->tx_buffer[0][0], 0xFF, PACKET_SIZE);
    memset(&overo_dev->tx_buffer[1][0], 0xFF, PACKET_SIZE);
    memset(&overo_dev->rx_buffer[0][0], 0xFF, PACKET_SIZE);
    memset(&overo_dev->rx_buffer[1][0], 0xFF, PACKET_SIZE);

    /*
     * Enable the SPI device
     *
     * 1. Enable the SPI port
     * 2. Enable DMA with circular buffered DMA (validate config)
     * 3. Enable the DMA Tx IRQ
     */

    // PIOS_Assert(overo_dev->cfg->dma.tx-> == CIRCULAR);
    // PIOS_Assert(overo_dev->cfg->dma.rx-> == CIRCULAR);

    /* only legal for single-slave config */
    PIOS_Assert(overo_dev->cfg->slave_count == 1);
    SPI_SSOutputCmd(overo_dev->cfg->regs, DISABLE);

    /* Initialize the GPIO pins */
    /* note __builtin_ctz() due to the difference between GPIO_PinX and GPIO_PinSourceX */
    GPIO_PinAFConfig(overo_dev->cfg->sclk.gpio,
                     __builtin_ctz(overo_dev->cfg->sclk.init.GPIO_Pin),
                     overo_dev->cfg->remap);
    GPIO_PinAFConfig(overo_dev->cfg->mosi.gpio,
                     __builtin_ctz(overo_dev->cfg->mosi.init.GPIO_Pin),
                     overo_dev->cfg->remap);
    GPIO_PinAFConfig(overo_dev->cfg->miso.gpio,
                     __builtin_ctz(overo_dev->cfg->miso.init.GPIO_Pin),
                     overo_dev->cfg->remap);
    GPIO_PinAFConfig(overo_dev->cfg->ssel[0].gpio,
                     __builtin_ctz(overo_dev->cfg->ssel[0].init.GPIO_Pin),
                     overo_dev->cfg->remap);

    GPIO_Init(overo_dev->cfg->sclk.gpio, (GPIO_InitTypeDef *)&(overo_dev->cfg->sclk.init));
    GPIO_Init(overo_dev->cfg->mosi.gpio, (GPIO_InitTypeDef *)&(overo_dev->cfg->mosi.init));
    GPIO_Init(overo_dev->cfg->miso.gpio, (GPIO_InitTypeDef *)&(overo_dev->cfg->miso.init));

    /* Configure circular buffer targets. Configure 0 to be initially active */
    DMA_InitTypeDef dma_init;

    DMA_DeInit(overo_dev->cfg->dma.rx.channel);
    dma_init = overo_dev->cfg->dma.rx.init;
    dma_init.DMA_Memory0BaseAddr = (uint32_t)overo_dev->rx_buffer[0];
    dma_init.DMA_MemoryInc  = DMA_MemoryInc_Enable;
    dma_init.DMA_BufferSize = PACKET_SIZE;
    DMA_Init(overo_dev->cfg->dma.rx.channel, &dma_init);
    DMA_DoubleBufferModeConfig(overo_dev->cfg->dma.rx.channel, (uint32_t)overo_dev->rx_buffer[1], DMA_Memory_0);
    DMA_DoubleBufferModeCmd(overo_dev->cfg->dma.rx.channel, ENABLE);

    DMA_DeInit(overo_dev->cfg->dma.tx.channel);
    dma_init = overo_dev->cfg->dma.tx.init;
    dma_init.DMA_Memory0BaseAddr = (uint32_t)overo_dev->tx_buffer[0];
    dma_init.DMA_MemoryInc  = DMA_MemoryInc_Enable;
    dma_init.DMA_BufferSize = PACKET_SIZE;
    DMA_Init(overo_dev->cfg->dma.tx.channel, &dma_init);
    DMA_DoubleBufferModeConfig(overo_dev->cfg->dma.tx.channel, (uint32_t)overo_dev->tx_buffer[1], DMA_Memory_0);
    DMA_DoubleBufferModeCmd(overo_dev->cfg->dma.tx.channel, ENABLE);

    /* Set the packet size */
    DMA_SetCurrDataCounter(overo_dev->cfg->dma.rx.channel, PACKET_SIZE);
    DMA_SetCurrDataCounter(overo_dev->cfg->dma.tx.channel, PACKET_SIZE);

    /* Initialize the SPI block */
    SPI_DeInit(overo_dev->cfg->regs);
    SPI_Init(overo_dev->cfg->regs, (SPI_InitTypeDef *)&(overo_dev->cfg->init));

    SPI_CalculateCRC(overo_dev->cfg->regs, DISABLE);

    /* Enable SPI */
    SPI_Cmd(overo_dev->cfg->regs, ENABLE);

    /* Enable SPI interrupts to DMA */
    SPI_I2S_DMACmd(overo_dev->cfg->regs, SPI_I2S_DMAReq_Tx | SPI_I2S_DMAReq_Rx, ENABLE);

    /* Configure DMA interrupt */
    NVIC_Init((NVIC_InitTypeDef *)&(overo_dev->cfg->dma.irq.init));
    DMA_ITConfig(overo_dev->cfg->dma.tx.channel, DMA_IT_TC, ENABLE);

    /* Enable the DMA channels */
    DMA_Cmd(overo_dev->cfg->dma.tx.channel, ENABLE);
    DMA_Cmd(overo_dev->cfg->dma.rx.channel, ENABLE);

    *overo_id = (uint32_t)overo_dev;

    return 0;

out_fail:
    return -1;
}

static void PIOS_OVERO_RxStart(uint32_t overo_id, __attribute__((unused)) uint16_t rx_bytes_avail)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    bool valid = PIOS_OVERO_validate(overo_dev);

    PIOS_Assert(valid);

    // DMA RX enable (enable IRQ) ?
}

static void PIOS_OVERO_TxStart(uint32_t overo_id, __attribute__((unused)) uint16_t tx_bytes_avail)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    bool valid = PIOS_OVERO_validate(overo_dev);

    PIOS_Assert(valid);

    // DMA TX enable (enable IRQ) ?

    // Load any pending bytes from TX fifo
    // PIOS_OVERO_WriteData(overo_dev);
}

static void PIOS_OVERO_RegisterRxCallback(uint32_t overo_id, pios_com_callback rx_in_cb, uint32_t context)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    bool valid = PIOS_OVERO_validate(overo_dev);

    PIOS_Assert(valid);

    /*
     * Order is important in these assignments since ISR uses _cb
     * field to determine if it's ok to dereference _cb and _context
     */
    overo_dev->rx_in_context = context;
    overo_dev->rx_in_cb = rx_in_cb;
}

static void PIOS_OVERO_RegisterTxCallback(uint32_t overo_id, pios_com_callback tx_out_cb, uint32_t context)
{
    struct pios_overo_dev *overo_dev = (struct pios_overo_dev *)overo_id;

    bool valid = PIOS_OVERO_validate(overo_dev);

    PIOS_Assert(valid);

    /*
     * Order is important in these assignments since ISR uses _cb
     * field to determine if it's ok to dereference _cb and _context
     */
    overo_dev->tx_out_context = context;
    overo_dev->tx_out_cb = tx_out_cb;
}

#else /* if defined(PIOS_INCLUDE_FREERTOS) */

static void PIOS_OVERO_RegisterTxCallback(uint32_t overo_id, pios_com_callback tx_out_cb, uint32_t context) {};
static void PIOS_OVERO_RegisterRxCallback(uint32_t overo_id, pios_com_callback rx_in_cb, uint32_t context) {};
static void PIOS_OVERO_TxStart(uint32_t overo_id, uint16_t tx_bytes_avail) {};
static void PIOS_OVERO_RxStart(uint32_t overo_id, uint16_t rx_bytes_avail) {};

#endif /* PIOS_INCLUDE_FREERTOS */

#endif /* PIOS_INCLUDE_SPI */

#endif /* PIOS_INCLUDE_OVERO */

/**
 * @}
 * @}
 */
